Hydraulic pump or motor



April 20, 1937. E. K. BENI-:BEK 2,077,389

' I HYDRAULIC PUMP OR MOTOR Fild Jan. 25, 1935 5 sheets-sheet 2 ZEEKEENEUEK April 20, 1937. A E. K. BENEDEK 2,077,389

HYDRAULIC PUMP 0R MOTOR Filed Jam 25, 1935 5 Sheets-Sheet 3 wv ena/oom la ZZEKZfA/E Ib' E @M Patented Apr. 2 0, 1937 annuo rum 'on Moron Elek E. Beneden, Bue @hic Application January 25, i935, Serial No. 3,@55

i12 Claims. (Cl. Mit-lidi) Yl'his invention relates to pumps and motors of the radial piston, variable displacement type and particularly to pumps and motors of this character adapted for providing high hydrostatic pressure for use in connection with heavy hydraulic power driven machines, transmissions, presses and the like, one of the purposes being to create a compact and elcient unit for hydraulically transmitting as much as 500 horsepower and above. l

Prior pumps of this general type comprise th usual driving and driven members with the radial pistons, rigidly or flexibly engaging one of the members and reciprocating in pump cylinders in the other for providing the necessary hydrostatic head'. However, in such prior structures, the pistons and their mountings not only perform their primary function as hydraulic members but prgvide the sole mechanical coupling means for transmitting driving torque from the driving member to the driven member. Necessarily, for providing the desired hydraulic pressure, the piston assemblages and their mountings are subjected to the very high radial compressive forces. concurrently, in order to drive the driven member through the medium of the piston assemblages, heavy tangentially or peripherally directed forces necessary for driving torque are transmitted to the various parts of the piston and cylinder assemblages, subjecting the parts to severe bending stresses and moments.

These stresses result not only in extremely high frictional resistances but also undue wear, especially between the pistons and the walls of their respective cylinder bores and between the piston crossheads and their respective guides. Since a close nt therebetween is necessary, the wear thus occasioned results in -short useful life of the pump. Obviously, these bending stresses are augmented disproportionately when simultaneous with the compressive radial reactances to which the pistons are subjected in providing the hydrostatic pressure. This conjoint effect, is such as to render the prior pumps practically useless for the higher pressures sought to be obtained by the present pump due tothe fact that the pistons of the former V seize in their respective cylinders as also do the crossheads in their guides.

In such pumps, the useful life inherent in the materials used is seldom reached, the failure being caused not by excessive slip and heat but by the fact that the pistons and their crossheads are rocked and forced out of coaxial position with respect to their cylinder and crosshead guide walls and seize therein so as to render further operation of the pump impossible.

Since, in such pumps, whether of the rf-shaped piston, integral plunger and crosshead type, the flexible crosshead type, or hollow plunger push pin type, the sole means of torque transmission between the driving and driven members are primarily the pistons and their cooperating cylinder walls, each piston must transmit from the driving member to its crosshead and thence to the driven member a force couple substantially equal to a part of the entire torque of the driving member inversely proportional to the number oi pistons employed.

The flexible crosshead type, due to the rocking of the push pins in the hollow plungers, is inadequate for proper torque transmission, the plungers themselves being small and the push pins necessarily smaller. It is clear therefore why the nexible piston type of radial pumps has never reached safely a capacity of more than horsepower. l

4The T-head piston type lends itself to higher capacities due to the more rigid structure of the pistons and their integral crossheads which make possible the transmission of a heavier torque. This type has been found useful up to 200 horsepower.

Such pumps may well bel designated collectively as coupling pumps""the expression being used in its literal sense, inasmuch as the sole mechanical coupling for transmitting torque from vthe driving to the driven member is the pump invention is to provide a pump or motor of the radial piston type in which the torque transmitting and coupling functions of the radial pistons are entirely eliminated and in which the driving torque between the primary and secondary rotors is transmitted by an eillcient mechanical coupling entirely independent of the piston assemblages themselves insofar as concerns torque transmission. y

Another object is to provide an improved 1'- shaped piston structure such'that no forces, other eliminated .and the pistons are subjected only to true radial reactance forces -so that not only is the power delivered to the piston for creating hy-` o -drostatic head utilized fully but also none of it is wasted or misapplied so as to create unnecessary stresses and friction'al resistance between the pistons and their cooperating mountings and cylinder walls.

A more general object is to provide a pump of this character in which any forces tending to tilt the rotor due to the torque applied to it from thev impeller shaft is overcome and resisted without A being transferred to the pistons or to the secondary rotor and in which all bearing surfaces and points of application of pressures between the component parts are symmetrical with respect to the axes of the piston so that an eillcient balance is provided throughout the mechanism.

Another object is to provide a stroke controlling mechanism which rotatably supports a secondary rotor in a simplified manner.

- A more specific object is the provision of a simplied means for mounting the pistonsin the piston actuating mechanism.

A marked advantage of my invention resides in the more eillcient operation of the apparatus resulting from the cooperative relations among the new coupling means, the new piston actuating means, and the piston assemblages themselves.

k'Other important features include individual reactance segments'for each piston, the manner in which theyare mounted in position relative to.

the secondary rotor, the manner of assembling and disassembling the driving coupling means between the rotors and their driving connection to -the primary rotor so as to eliminate both mechanical unbalance and hydrostatic deflection oi' the rotating parts.

Other objects and advantages will become apparent from the following specification wherein reference is made-to the drawings in which Fig. 1 is a longitudinal side elevation of a pump iembodying the principles oi' the present invenion; v

Fig. 2 is an end elevation of the pump illustrated in Fig. 1 taken from the valve end thereof;

Fig. 3 is an enlarged horizontal sectional view of the pump taken on a plane indicated by the line 3-3 of Fig. 2;

Fig. 4 is a transverse sectional view of the pump taken on a plane indicated by the line 4 4 in Fig. 1;

Fig. 5 is a perspective view of one of the segmental reactionrblocks; v

Fig. 6 is a perspective view of the piston connecting spring;

Fig. 7 is a perspective view of one of the component elements of the driving coupling; and

Fig. 8 is a fragmentary transverse, sectional view of the pump driving coupling taken on the line 8--8 of Fig. 3, a portion thereof being taken on the line 8'-8' of Fig. 3 for clearness in illustration. 1

aovaase Referring to the drawings, which illustrate a preferred embodiment of my invention. the pump or motor mechanism is enclosed in a housing comprishing a central cylindrical body portion I, closed at the ends by end portions) and 3 respectively. The end portion 3 is provided with an enlarged heavy hubv I adapted to receive the valve pintle for the rotors, later to be described. The endportion 2 is provided with an outwardly protruding bell-shaped portion 5 to accommodate the balanced rotor of the mechanism. Part way out radially. from the axis of the hub l, the end portion 3 is provided with an internal annular recess l, the end portion 2 being provided with a coaxial internal annular recess 6 of equal diameter. `These recesses receive the outer races 8 of anti-friction bearings Ill-I0, the radial end walls'of the recesses forming abutments for resisting axial outward displacement of the'bearing races 8. Complementary inner bearing races 9 are mounted on coupling members I I, later to be described, and through the, medium of the coupling members, rotatably support the driving rotor I2. The anti-friction bearings l0 are of substantially the samesize for both races and are of theheavy duty type operating in circumferential channels'in the racesso as to resist axial displacement of the races and consequently operate as thrust bearings as well as resisting radial pressures.

The primary rotor of the mechanism comprises a piston cylinder barrel I2 having at one end an annular reduced diameter hub portion I3 on which ,is telescopically received a coupling member II which, in turn, engages the inner bearing race-9 at that end so that the reaction forces transmitted to the bearings I0 from the end portion 3.of the casing are directly transmitted thereby to the coupling member II and barrel I2. A

corresponding coupling member II is providedat the opposite end of the barrel I2 and cooperates in the same manner with the bearing race 9 at that end. The coupling members II are secured against axial displacement toward the longitudinal midportion of the barrel I2 by radial shouiders Il and I5 on the barrel I2, at the inner limits of the hub portions. Relative axial separation of the members II is resisted by radial Walls of the recesses 6 and 1 of the housing, through the medium of the bearing races 8 and 9, and bearings Ill. Thus the coupling members are so ilxed in axial relation to the barrel I2 as to form therewith'a substantially unitary structure.

As better illustrated in Fig. 8, each of the coupling members II has an integral radial flange I I', later to be described. The proper angular relation of the coupling members I I is maintained by appropriate feather keys 56 between the coupling members II and the barrel I2. In addition an accurate snug iit is provided between the annular hub portions of the coupling members II and corresponding ends of the barrel. In case of large units the hub portions of the barrel I2 may be tapered and the coupling members II corre` spondingly internally tapered and fitted rmly thereon to prevent developing of any looseness therebetween.

The barrel l2 is provided with an axial .borev extending entirely therethrough, the end of the axial bore adjacent the driving end of the barrel being tapered, as indicated at I8, to receive the complementary tapered end 23 of the main impeller shaft 24, the shaft being drawn tightly into the tapered bore of the barrel as by a suitable pling elements il. Prom slightly beyond this point toward the opposite' end of the barrelextends a valve portion il of the axial bore of the barrel. Rlgidly mounted in the hub 4 at the `opposite end of the casing from the impener shaft is the enlarged shank of a pintle 2 1. the' pintle extending from thehub I into the axial bore of the barrel into closely spaced endwise relation to the end portion o i' the impeller shaft. The pintle 2l is provided with a valve portion 2l complementary to the valve portion' It of the barrel and preferably fitting the wall of the portion I8 with a slight taper fit in such manner that any axially exerted pressure component due tothe taper may be readily taken up by the anti-friction bearings it. The valve portions 2B of the pintle and il of the barrel bore are fitted with a highly polished hydraulic nt so asto permit rotation ofthe barrel thereabout without' undue leakage of oil therebetween. 'I'he end portion Il of the barrel adjacent the hub 4 is provided with acounterbore I3' of sumcient length and diameter to provide radial clearancebetween the, enlarged end ofthe pintle and the barrel' and to provide axial clearance, as indicated at 20, between the shoulder oi.' the pintle 2l and the radial shoulder of the barrel at the end ofthe valve portion. By this arrangement, the heavy rigid portion of the pintle may be brought as near as possible to the valve portion of the pintle so as to provide greater rigidity to better withstand the hydrostatic load imposed on the valve portion 26. s

As previously stated, the end of the hub portion it of the barrel in cooperation with the hub portion ofthe coupling member ill at that end of the barrel rigidly mounts therotary barrel for torque transmission. The corresponding mounting at the other end of the barrel l2 likewise functions so that tipping of the barrel relative to the axis of the pintle, which usually results ,A from torque transmission from an impeller acting on one end of the barrel, is iully eliminated.

The valve portion 26 of the pintle is provide with the conventional reversibleports, indicated at 28 and 29, the ports being separated by the usual bridge portions 26' and 28" as vbetter .illustrated in Fig. 4, which bridge portions terminate circumferentially in'to appropriate radial pockets The piston cylinders i1 of the rotor i2 are ar-v ranged in a radial plane so that their axes lie midway between the bearings il of the rotor i2.

Each or the coupling members i I is provided with a circular radial ilange Il', as previously inentioned. these flanges extending radially parallel to the pistons and being positively secured to respective end portions of the rotor I2 through the medium of their axially extending hub portions. In each radial flange portion il are a plurality of circumferentially spaced radial slots Il. opening radially outwardly. Reciprocably mounted within each slot isa coupling block 4l. each cou- Plins block being provided with a radial prismatic portion ll which is received between the side walls of the slot 4l as a guideway and is reciprocableradially therebetween. From the face ad- Ijacent the barrel i2 of each prismatic portion of each coupling block u, protrudes a crosswise portion Ill"` which is received in a tangential slot 31"' formed in a coupling plate complementary to the coupling "member `i I, as better illustrated in Ii'ig. 3, each coupling plate llgforming a. part not only of the coupling structure but also of the `piston actuating assembly. Each plate 39 is provided with'a piston actuating shoulder positioned to underlie the piston thrust plate, later to be described, in contact therewithso as to lift the thrust plate lfor moving the piston associated therewith on the suction stroke. These complef mentary contact surfaces, indicated at 8S", of

each plate 39 and associated thrust plate are preferably tangentially extending planes, so that the thrust Iplate is guided by the coupling plate 3e during the successive cycles of the pump and pre- 'vented from rocking,A or tilting. The coupling plates 3l extend generally radially and near their outer margins are provided with arcuate shoulders 'It' which are engaged with and rigidly secured to the secondaryrotor 42. The cooperating shoulders of' the 4coupling plates 2lit and the 1 secondary rotorv will thus transmit any radial thrust imposed on the plates directly to the secondaryrotor 43. Corresponding coupling plates areprovided at opposite ends oi the secondary coupling-member t0 and plate 38 fixed axially of the rotor with respect to the remainder of the assembly and to each other. Thus during the driving operation, each of the blocks it can shift radially to compensate for the radial component ofthe eccer'rtricity of the rotors and,

through the medium of the slot tiimand cross member 40", can shift slightly circurnfex'entiailyy relative .to the associated plated@ and thereby compensate for the circumferential component l0i' the itci'itridity. It should 'be noted that each coupling block l@ and its mountings are positioned circumferentially of the rotors so as to lie.in a plane dened by the axes of the pintle and o the respective pistons. Consequently all torque forces can be more eilciently .applied close to and symmetrically with respect tothe pistons. a

` It should benoted that the coupling blocks 40 reciprocate in the slots 48 a distance equivalent to the maximum pump stroke and'the torque transmission from the primary rotor to" the secondary yrotor through the coupling occurs substantially at the vradial distance of the tan# I soA gential lug 40" from the axis of the pintle. Due

to this' long torque arm, which is greater than the length of thepiston and even greater than the radial distance of thrust plates or crossheads which in conventional pumps'carry the torque,

ing pistons.

the torque is applied to the secondary rotor near its outer limit and the secondary rotor mecha.- nism therefore is subjected to lower. bending stresses. Since most of the driving torque is transmitted by the blocks 40 they are preferably of forged alloy steel, heat treated, hardened and ground so that they will stand not only great internal stress but will have wear resisting and smooth sliding coupling surfaces. Each of the radial cylinders in the rotor I2 is arranged in the plane of the longitudinal midportion of the portion 26 of the'pintle and in the longitudinal midportion of the rotor I2, for additional symmetry and balance. Each cylinder I isi-in communication with the pintle ports 28 and 29 successively during each rotation of the rotor I2 so that the working fluid may be drawn in through the one port and expelled from a cylinder at the other port. Each cylinder borek receives, with la snug and eilcient hydraulic nt, a piston 33, the outer end of which is spherical, as indicated at 35. The piston 33 has an annular groove 35 near its outer end which defines a neck portion 34 between the end or head 35 and the main body of the piston. The annular groove 35 is adapted to receive a connecting spring 31 which is split to permit contraction and to accommodate the spring when contracted. Outwardly from the end of the piston is a thrust plate 38 having a radial recess 38' for receiving the outer end portion of the piston to a point inwardly beyond the groove 35. 'Ihe side walls of this recess are provided with an annular groove 38" positioned to lie in the plane of the neck portion 34 or groove 35 when the end of the cylinder head rests against the bottom of the recess. 'This recess or counterbore 38' in the thrust plate 38 has a somewhat larger diameterthan the outside diameter of the piston head so that at no time will it be possible for the side walls of the recess to engage the piston and transmit to or receive from the piston any twist or turning moment or reactionary force. Since the piston head is spherical, and is the only point of contact, only radial thrusts can be delivered at any time by the thrust plate to the piston o'n the pressure stroke so long as the thrust plate is both close to and normal to the axis of the piston. 'I'he piston is secured for limited floating movement relative to the thrust plate by compressing the spring 31 into the groove 35 of the piston then inserting the two into the thrust plate recess 38' and permitting the spring to r assume its normal expansion and thus bridge between the groove in the thrust plate and the groove 35. The spring therefore loosely connects the piston and thrust plate for operating the piston on the suction stroke.

Each thrust plate 38 has a tangential plane outer face whichA abuts the complementary inner face of a segmental bearing plate 42 carried by the secondary rotor 43, so that the thrust plate and bearing plate may shift relatively to and fro in the direction of travel of the rotors to compensate for ecoentricity. Guideways 39" are provided in the coupling plates 39 for snugly engaging the opposite edges of the thrust plates so that the thrust plates may always be substantially normal to the axes of their cooperat- It will be noticed that the member 38 has been termed fthrust plate instead of "crosshead as obviously theplate is not a driving crosshead for the piston in the same manner as the usual crossheads. It can -exert no or other elements indicated at 44".

other than radially acting forces on the piston and its share of the driving torque of the pump is limited only to the inertia its own body adds to the rotor mass. In fact, the piston head 35 shifts the thrust plate itself back and forth the very slight amount necessary along the complementarybearing plate 42, by means of the radialY thrust due' to the hydrostatic load on the piston. Thus no lateral contact between the two is needed during the pressure cycle to shift it through-the medium of the piston head 35. `During the suction cycle the centrifugal force is sufcient to slidably shift the thrust plate along the bearing 42, only a slight lateral reac'tance between the piston hea'd 35 and the walls of the thrust plate recess 33 .beingl necessary to resist this centrifugal force. It is noted that the centrifugal force acts to urge the thrust plate 33 in the proper direction during the pressure stroke. In this manner substantially all force required to compensate for eccentricity of the rotor during part of the rotation is provided without even the necessity of contact between the circumferential wall of the piston head 35 and the circumagainst the secondary rotor 43..by,positive hydro-'ff' static force as well as centrifugal' force of its own. The studs, therefore, may slidably engage the bearing plates 42. The secondary rotor member 43 forms the inner ring of its supporting antifriction bearings 44 which cooperate with a stationary housing or reactance ring 45. For ease in installation, the bearings 44 may be held in place by axially separate cage members 44 which are held together by means such as the screws The reactance ring 45 is provided with a suitable means, such asindicated at 45', to receive the usual stroke control actuating means, indicated at 48, for shifting the axis of the ring 45. The ring 45 is maintained parallel to the axis of the barrel I2 by the usual abutments within the casing, not shown, and guided thereby during such movement. Within the casing I are abutments 41 for limiting the movement of the ring 45 for extreme adjustment of stroke. If. in larger units the friction between the abutment surfaces and ring 45 make shifting of the ring diillcult,

anti-friction bearings may be provided theresetween.

It is apparent that the relation of each thrust plate 38 and its associated piston 33 is semifloating, theradial load transmission and the centrifugal force of the piston during the pressure cycle being always suilicient to shift the sliding thrust plate in its real or true path along the bearing plate 42 and guideway I39". Thus by virtue of the novel coupling connection between the rotors, the novel mounting of the pistons in the thrust plates, and of the primary rotor in the casing, torque can be applied to one end of the rotor I2 and transmitted to the secondary rotor'without torsional stress and in turn transmitted to the piston as a thrust having none but a radial component.

Due to the symmetrical arrangement of the parts of the coupling and the bearings I0 at the opposite sides of the pistons and equidistant from 'the piston axes,- overbalance stresses, due to driving the rotor from one end and due tohyafnamreactances, are substantially eliminated. It will be clear from the above description that the manner in which the pistons are mounted in the thrust plates would be eiiective in thosei ate slip and low operating temperature are obtained, the mechanical load being properly directed by the rigid coupling directly on the rigid 'couplings and the driving torque directly transmitted from one rotor to the other so that all shocks and torsional oscillations of the secondary rotor or the piston actuating reactance assemblies are relieved and the pistons, due to the delivered radial thrusts, are4 substantially entirely relieved from wall friction and bending and tilting "stresses, and all forces acting thereon are utilized fully in performing the primary functions of suction and delivery of suitable hydraulic pressure. By the combination of the independent mechanical couple between the rotors and the base of piston mountings in the reactance means, it is possible to provide a pump of the radial piston type in which the forces introduced are utilized throughout most enlciently and no part of such f'forces is directed so as to be not only wasted but transformed into wear of the working parts.

` Having thus described my invention,

I claim:

l. In a pump or motor oi the character described, a casing, an internal annular bearing race within the casing, anti-friction bearings in A said race, a cooperating inner bearing race within the casing, a rotor within the casing coaxial with said races and having a radially extending body and a hub protruding from the body at one end into and coaxial with the inner race and spaced radially therefrom, a. secondary rotor mounted within the casing, coupling means drivingly connecting the rotors and an annular hub on the coupling' means extending between the inner race and the rotor hub and having its circumferential surfaces in tight iltting contact with said rotor hub and inner bearing race respectively and said coupling means having a radial portion contiguous to the hub portion and extending between the radially extending body and adjacent end oi said inner race and having its opposite face in juxtaposition with the said body and inner race for constraining said radial portion to ilxed position axially of the axis of rotay tion.

2. In/a device of the character described, a rotor having a plurality of circumferentially spaced radial cylinders, pistons reciprocable therein, a reactance rotor eccentric with respectto the cylinder rotor, a chordal bearing surface on the reactance rotor, a thrust plate having a plane bearing surface complementary to said chordal face, said thrust plate having a recess' at its inner face extending normal to the axis Aof recess. a contractable spring disposed in the piston groove and contractable therein to permit insertion of the piston and spring together into said recess, whereby the spring may expand bridge between said' grooves forl iloatinglyv connecting the piston and thrust plate with the piston side walls. spaced from the side walls of the thrust plate recess. and said recess having an abutment in the end wall thereof engageable with the end of the piston when the piston is .connected to the thrust plate.

3. In a pump or motor oi' the character described comprising primary and secondary rotors,

lone rotor having a` cylinder, valve means therefor, a piston carried by said cylinder and reciprocable radially thereof, a thrust plate interposed betwen the rotors, means mounting and guiding said thrustplate for movement radially only with respect to the rotor carrying the plsthe recess and cooperable with said piston shoulder for connecting the piston to the thrust plate with the piston side walls in spaced relation to the side wall of the recess and additional means operatively connecting the rotors for torque transmission independently of the pistons.

4. In a pump or motor, a casing, a primary rotor and a secondary rotor, means rotatably supporting-said rotors in said casing, said 'rotors having substantially parallel axes of rotation, means mounting one of said rotors for movement into different adjusted positions wherein its axis is parallel to and oiset from the axis of rotation of the other rotor, means to adjust said one rotor for changing the relative position of said Aparallel axes, a radial series of radial pistons reclprocably mounted in said primary rotor and actuated radlally'by said secondary rotor, coupling means between said rotors at each side of the pistons, said coupling means including a driving hub mounted between the primary rotor and itsassociated support and having a radial flange disc,

a driven disc carried by the said secondary rotor and extending parallel to said driving disc, and Aplanetating means between said discs` and connecting the discs to positively couple said driving and driven members for rotation together lnall adjusted positions of said one rotor.

5. In a rotary, radial piston pump or motor, a primary rotor, a secondary rotor in eccentric relation thereto, one of said rotors having a p lurality of radial cylinders, .pistons in said cylinders respectively, means in valving cooperation with the cylinders, thrust means connected to the pistons respectively and operatively interposed between the other of said rotors and the pistons respectively for reciprocating the pistons, said thrust means being shiftable to and fro along the path of rotation for compensating for tangential components of eccentricity of said rotors, and coupling means disassociated from said thrust means for drivingly connecting the rotors for torque transmission, said coupling means comprising a rigid radial iiange in fixed position on one rotor at one side of the pistons, a plurality of circumferentially spaced guidewaysl therein, another radial iiange in fixed positon on the other rotor in substantially face .to face relation to the first flange, a plurality of circumferentially spaced complementary guideways in said other radial flange and each complementary guideway extending operatively at right angles to and associated one of the rst guideways and aligned therewith longitudinally of the rotors, rigid coupling elements carried by said flanges and said elements having portions accommodated in and slidable along said aligned complementary guideways respectively concurrently and drivingly connecting the rotors.

6. In a rotary, radial piston pump or motor, a cylinder rotor having a plurality of radial cylinders, valve means for the cylinders, a reactance rotor in eccentric surrounding relation to the cylinder rotor and having a circumferential wall and radial flange walls defining an internal re'- cess open toward the cylinder rotor, pistons in the cylinders respectively, valve means for the cylinders, thrust means disposed in the recess and mounted for oscillation therein, and cooperating respectively with the pistons for actuating the same, a radial flange Wall on the cylinder rotor having a face substantially juxtaposed to the outer radial face of one of said ange walls, a tangential guideway ln one of said juxta posed ange walls, a radial gudeway in the other of said juxtaposed walls, said guideways being aligned longitudinally of the rotor with each other, a coupling element carried by said juxtaposed walls and entirely disassociated from said thrust means and having a tangential portion accommodated in and slidable along the tangential guideway, and a portion accommodated in and slidable along the radial guideway.`

I. In a rotary, radial piston pump or motor, a pair of rotors in eccentric relation to each other, radial piston and cylinder assemblies carried by the rotors and operated thereby consequent upon concurrent rotation of the rotors, valve means for the assemblies, one of said rotors being in surrounding relation to the other rotor, a chordal guide carried by one rotor in fixed position relative thereto and spaced from the axis of rotation thereof, a radial guide carried bythe other one of said rotors -and in fixed position relative thereto, and extending radially inwardly and outwardly beyond both radial limits of the, chordal guide, and a coupling element having portions engaged with and slidable along said guides respectively concurrently, and being operative independently of and disassociated from the piston and cylinder assemblies.

8. In a rotary, radial piston pump or motor, a cylinder rotor having a plurality of radial cylinders, a reactance rotor in surrounding rela-` tion thereto, pistons in said cylinders respectively,

valve means for the cylinders, said reactance rotor having a circumferential reactance wall and radial ange walls at each end of the circumferential wall and defining therewith a circum`A ferential recess open toward the cylinder rotor, shoulders on the radially inward margins of said radial walls for engaging the inner Working surfaces of piston heads to operate the' pistons on their suction strokes, heads connected to the pistons and disposed in said recesses with their inner faces supported on said shoulders, thrust means interposed between the heads and circumferential wall of said reactance rotor, chordal grooves in said radial walls, radial flanges carried by the cylinder rotor and lying alongside said radial walls of the surrounding rotor in substantially face to face abutting relation thereto, radial 4grooves in said flanges aligned longitudinally of the rotors with said chordal grooves respectively, coupling blocks carried by said flanges in said guideways and reciprocable radially thereof and having portions accommodated fox` sliding action in said chordal grooves.

9. In a rotary, radial piston pump or motor, a cylinder rotor having a plurality of radial cylinders, pistons in the cylinders respectively, valve means for the cylinders, reactance rotor means in eccentric surrounding relation to the cylinder rotor,v and comprising radial wall elements arranged at opposite sides of the plane of the pistons, said pistons having portions extending between said radial wall elements, guideways in said radial wall elements for cooperation with the pistons, thrust means operating in said guideways and connected with the pistons respectively for actuating the pistons consequent upon concurrent rotation of the cylinder rotor and reactance rotor means, a reactance stator in fixed position longitudinally of the cylinder rotor, means mounting the radial wall elements in the stator for rotation and axially floating movement, and radial flanges on the cylinder rotor at the outer faces of said radial wall elements and having faces juxtaposed to theouter radial faces of said radial wall elements respectively for constraining the said elements to fixed axial position with respect to the cylinder rotor.

10. In a rotary, radial piston pump or motor, a casing, a cylinder rotor in the casing and having a plurality of radial cylinders, a reactance rotor means in surrounding relation thereto, pistons in said cylinders respectively, valve means for the pistons, said reactance rotor means comprising radial wall elements at opposite sides of the plane of the pistons, said pistons having portions extending between the radial wall elements, guideways in said radial wall elements for cooperation with the pistons, thrust ,means operating in said guideways and connected with the pistons respectively for actuating the pistons consequent upon concurrent rotation of the cylinder rotor and reactance rotor means a reactance stator in fixed position longitudinally of the cylinder rotor, means mounting the radial wall elements in the stator for rotation and axially floating movement, radial anges carried by the cylinder rotor at the outer faces of said radial wall elements and having faces juxtaposed to the outer radial faces of said radial wall elements respectively for constaining the said elements to fixed axial position with respect to the cylinder rotor, anti-friction elements at each end of the cylinder rotor and mounting the cylinder rotor in the casing in fixed axial position, said cylinder rotor having end wall portions, and said anti-friction elements including inner race members abutting the radial anges and holding the radial anges in fixed axial position and abutting relation to said endwall portions of the cylinder rotor.

11. In a rotary radial piston pump or motor, a primary rotor, a secondary rotor in eccentric relation thereto, radial cylinders carried by one rotor. pistons carried in the cylinders respectively,

thrust means on each piston operatively connecting the pistons to the other rotor for actuation of the pistons consequent upon concurrent rotation of the rotors,v valve means for the cylinders, and positive coupling means between the rotors and disassociated from the pistons and thrust means, said coupling means comprising a plurality of guides on one rotor uniformly distributed circumferentially thereof, complementary guides carried in the other rotor and respective to the liliA aomsso l 7 rst guides Vand extending at right angles each to an associated one oi the nrst guides respectively in the plane parallel to the plane of the rst guides, independent coupling elements cooperat- 5 ing one continuously with each pair of associated guides for drivingiy connecting the rotors while compensating for tangentialy and radial components'of eccentricity, each element being entirely disconnected from and operable independ- 10 ently of the remaining coupling elements, whereby torque transmission between the rotors is substantially uniform during the operation thereof.

12. In a rotary radial piston pump or motor, a primary rotor, a secondary rotor meansior sup- 15 porting the secondary rotor for-addustment into diiferent positions wherein its axis is parallel to andloilset from or co-#incident with the axis of the primary rotor, means for adjusting the secondary rotor, radial cylinders carried by one rotor. pistons 20 carried in the cylinders respectively. thrust means on each piston operatively connecting the pistons to the other rotor for actuation 'of the pistons consequent upon "concurrent rotation of the rotors, valve means for the cylinders and positive planetating coupling means between the rotors 5 and disassociated Vfrom the pistons and thrust means, said coupling means comprising independent coupling elements uniformly distributed circumierentially of the rotors and each coupling element being continuously connected to both 10 rotors for planetating movement with respect to the combined rotors for drivingly connecting the rotors while compensating for tangential and radial components of eccentricity, each element being entirely disassociated from the remainingl 15 coupling elements andcontinuously operable in all relatively adjusted positions of said rotors. whereby torque transmission between the rotors is substantially uniform during the operation thereof.

ELEK K. BENEDEK. 20 

